Roasting-furnace.



No. 809,953. PATENTEDTJAN. 16, 1906. o. HOFMANN.

ROASTING FURNACE.

APPLICATION FILED FEB. 19, 1904.

UNlfTED STATES PATENT @FFIQE.

OTTOKAR HOFMANN,'OF ARGENTINE, KANSAS, ASSIGNOR TO THE UNITED ZINC AND CHEMICAL COMPANY, OF KANSAS CITY, MISSOURI, A (JOR- PORATION OF NElV JERSEY.

ROASTlNG-FURNACE.

Specification of Letters Patent.

Patented Jan. 16, 1.906.

To (I/Zl [uh/mt it may concern;

Be it known that I, OTTOKAR HoruANx, a citizen of the United States, residing at Argentine, in the county of yandotte and State of Kansas, have invented certain new and useful Improvements in Roasting-Furnaces, of which the following is a specification.

In certain classes of roasting-furnaces hollow iron stirringarms are used which are fastened to a vertical hollow shaft. As sulfur at a high temperature attacks the iron, it is necessary in order to lengthen the life of the iron parts to cool the shaft and arms. This is usually done by keeping the shaft and arms full of a cooling fluid, as a circulating body of water or an air-current or a mixture of air and steam forced through the arms and shaft. If water is used in the above manner, the arms have to be rigidly and tightly fastened to the hollow shaft to avoid leaking joints, the degree of cooling cannot be regulated, and in certain instances such a radical cooling is more than required and is injurious to the process by withdrawing too much heat from the ore. Further, it has not been found possible when water is used to regulate the temperatures at which it is desirable to keep the stirring arms at the different roastingshelves, and in case of a break of an arm a large body of water enters the hot furnace with danger of an explosion from the rapid generation of steam, and in case of breakage the stirring-arms cannot be changed for new ones without first cooling the furnace. With air or air-and-steam cooling the temperature of the arms and shaft can be regulated and the arms can be replaced by new ones while the furnace is hot; but in many instances a greater cooling is required than can be secured by air or a mixture of air and steam or with steam alone, and yet such a radical cooling as water secures when the parts are kept full may not be required-in fact, may be injurious. Furthermore, it is not always con venient to use exhaust-steam or to employ a blowing-machine. To meet these requirements and to produce a cooling which is under perfect control and with a wide range of efficiency, 1 have invented a cooling device illustrated in the accompanying drawings, in which Figure 1 represents a vertical section of a roasting-furnace of that class to which my invention is specially adaptable. Fig. 2 is a detail View of one form of spraying-nozzle which may be employed in carrying out my invention.

The furnace, while it may be of any desired class, is shown as arranged for roasting sulfureted ore very rich in zinc blende.

A A A are the roasting-hearths, while B B, &c., are hollow hearths or platforms with fireflues.

S is a vertical hollow shaft su )ported at the lower end by a step C, vertically adjustable by a screw D, and at the upper end by a box M, and said shaft carries the detachable hollow stirring-arms IV E is a vertical water pipe extending through the shaft S and provided with branch pipes F, each of which enters one of the hollow arms through an opening a at the inner end thereof. Each of said branch pipes F is provided at its outer end with spraying means by which the water is delivered to the arm in the form of spray or aplurality of streams. Two forms of such spraying means are illustrated in the drawings, one shown at the right of the central vertical water-pipe in Fig. 1 and also in Fig.7 2 and the other shown at the left of the said vertical pipe in Fig. I. The former of said means comprises a nozzle-section having a plurality of openings or nozzles at its end, While the other form comprises a laterally-perforated extension of the branch water-pipe extending through a considerable portion of the length of the stirring-arm. Both forms, however, are adapted to discharge the water from the branch pipes F into the stirring-arms in the form of spray or a plurality of fine streams, as distinguished from delivering a single solid stream to each arm In either case the wa ter is injected into the hot arms and will evaporate rapidly and will cool the arms proportionately to the amount of water injected, and the generated steam leaving the arms through the openings or passages (Z, enters the shaft around the pipes F, through which shaft it flows upward and escapes and by doing so cools the same. If more water is injected than will be evaporated, the same will flow down the inside of the shaft, accumulate at the bottom, and leave the same through a pipe Y, which discharges into a circular trough X, from which it flows by an overflowpipe Z.

The vertical pipe E is at the top connected with a water-supply pipeV by a suitable joint, or it can be extended a few feet to give some pressure to the water and can be fed by a faucet through a funnel.

It will be seen that by the means set forth the operator has the degree of cooling under complete control, as where roasting-shelves are the hottest and a more effective cooling of the arms is required the branch pipes are provided with larger nozzle-openings or with larger holes to inject a larger supply of water. It will also be seen that the means described permits the changing of the arms while the furnace is hot, and there is no danger of steam explosion in case an arm breaks.

A more minute description of the furnace represented by the drawings is not nesessary than shown by the design, as my invention may be applied to various forms of furnaces and as the said construction is fully set forth in my application filed August 29, 1903, Serial No. 171,238.

Without limiting myself to the construction shown, I claim- 1. The combination in a roasting-furnace, of a pipe, hollow radial arms extending therefrom, and water-supply pipes arranged to deliver water into said arms said water-supply pipes being provided with spraying means, substantially as set forth.

2. The combination in a roasting-furnace, of a pipe, hollow radial arms extending therefrom, and water-supply pipes provided with means to spray water in regulated streams into said arms, substantially as set forth.

3. The combination in a roasting-furnace, of a pipe, hollow radial arms extending therefrom, water-supply pipes provided with means to spray water into said arms, and passages whereby steam can escape from the arms into said pipe, substantially as set forth.

4. The combination in a roasting-furnace, of the successive hearths, a hollow shaft or pipe S extending through the hearths, and supported to rotate, hollow arms carried by the shaft, a water-pipe extending through the shaft S, and branches extending from the water-pipe into said arms and each provided with openings for spraying water into the arms, substantially as set forth.

5. The combination in a roasting-furnace, of the successive hearths, a hollow shaft S extending through the hearths, and supported to rotate, hollow arms carried by the shaft, a water-pipe extending through the shaft S, and branches extending from the water-pipe into said arms and each provided withopenings for spraying water into the arms, said openings being proportioned to the amount of water to be sprayed, substantially as set forth.

6. The combination in a roasting-furnace, of the successive hearths, a hollow shaft S extending through the hearths, and supported to rotate, hollow arms carried by the shaft, a water-pipe extending through the shaft S, branches extending from the water-pipe into said arms and each provided with means for spraying water into the arms, a free outlet at the lower end of the shaft S, a discharge-pipe Y communicating therewith, and a trough X below the discharge-pipe, whereby to prevent accumulations of water in the shaft, substantially as set forth.

7. The combination in a roasting-furnace, of a shaft, hollow arms extending radially from the shaft, water-supply pipes and means on said pipes for spraying water against the inner faces of the side walls of each arm, substantially as set forth.

8. The combination in a roasting-furnace, of a shaft, hollow arms extending radially through the shaft, water-pipes arranged within and extending longitudinally of the arms, each of said pipes being provided with waterspraying means, and means for supplying water to said pipes, substantially as set forth.

In testimony whereof I have signed my name to this specification in the presence of two subscribing witnesses.

OTTOKAR HOFMANN.

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